Claude Sonnet 4.5 vs Claude Sonnet 4.6
Claude Sonnet 4.5 (2025) and Claude Sonnet 4.6 (2026) are frontier-tier reasoning models from Anthropic. Claude Sonnet 4.5 ships a 200K-token context window, while Claude Sonnet 4.6 ships a 1M-token context window. On MMLU PRO, Claude Sonnet 4.6 leads by 1.3 pts. On pricing, Claude Sonnet 4.5 costs $3/1M input tokens versus $3/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Claude Sonnet 4.6 fits 5x more tokens; pick it for long-context work and Claude Sonnet 4.5 for tighter calls.
Decision scorecard
Local evidence first| Signal | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Decision fit | RAG, Agents, and Long context | Coding, RAG, and Agents |
| Context window | 200K | 1M |
| Cheapest output | $15/1M tokens | $15/1M tokens |
| Provider routes | 7 tracked | 5 tracked |
| Shared benchmarks | 1 rows | MMLU PRO leader |
Decision tradeoffs
- Claude Sonnet 4.5 has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags Claude Sonnet 4.5 for RAG, Agents, and Long context.
- Claude Sonnet 4.6 leads the largest shared benchmark signal on MMLU PRO by 1.3 points.
- Claude Sonnet 4.6 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Claude Sonnet 4.6 uniquely exposes Code execution in local model data.
- Local decision data tags Claude Sonnet 4.6 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
Claude Sonnet 4.5
$6,150
Cheapest tracked route: Microsoft Foundry
Claude Sonnet 4.6
$6,150
Cheapest tracked route: OpenRouter
Estimated monthly gap: $0.00. Batch, cache, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter, Anthropic, and AWS Bedrock; start route-level A/B tests there.
- Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
- Claude Sonnet 4.6 adds Code execution in local capability data.
- Provider overlap exists on Microsoft Foundry, Anthropic, and GCP Vertex AI; start route-level A/B tests there.
- Cheapest tracked output pricing is tied, so migration risk shifts to quality, latency, and provider packaging.
- Check replacement coverage for Code execution before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-09-29 | 2026-02-17 |
| Context window | 200K | 1M |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Proprietary | Proprietary |
| Knowledge cutoff | 2025-12 | 2025-12 |
Pricing and availability
| Pricing attribute | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Input price | $3/1M tokens | $3/1M tokens |
| Output price | $15/1M tokens | $15/1M tokens |
| Providers |
Capabilities
| Capability | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
Benchmarks
| Benchmark | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| MMLU PRO | 86.0 | 87.3 |
Deep dive
On shared benchmark coverage, MMLU PRO has Claude Sonnet 4.5 at 86 and Claude Sonnet 4.6 at 87.3, with Claude Sonnet 4.6 ahead by 1.3 points. The largest visible gap is 1.3 points on MMLU PRO, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on code execution: Claude Sonnet 4.6. Both models share vision, multimodal input, reasoning mode, and function calling, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Claude Sonnet 4.5 lists $3/1M input and $15/1M output tokens, while Claude Sonnet 4.6 lists $3/1M input and $15/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Claude Sonnet 4.5 lower by about $0 per million blended tokens. Availability is 7 providers versus 5, so concentration risk also matters.
Choose Claude Sonnet 4.5 when vision-heavy evaluation and broader provider choice are central to the workload. Choose Claude Sonnet 4.6 when coding workflow support and larger context windows are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Claude Sonnet 4.5 or Claude Sonnet 4.6?
Claude Sonnet 4.6 supports 1M tokens, while Claude Sonnet 4.5 supports 200K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Claude Sonnet 4.5 or Claude Sonnet 4.6?
Claude Sonnet 4.5 is cheaper on tracked token pricing. Claude Sonnet 4.5 costs $3/1M input and $15/1M output tokens. Claude Sonnet 4.6 costs $3/1M input and $15/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Claude Sonnet 4.5 or Claude Sonnet 4.6 open source?
Claude Sonnet 4.5 is listed under Proprietary. Claude Sonnet 4.6 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Claude Sonnet 4.5 or Claude Sonnet 4.6?
Both Claude Sonnet 4.5 and Claude Sonnet 4.6 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for multimodal input, Claude Sonnet 4.5 or Claude Sonnet 4.6?
Both Claude Sonnet 4.5 and Claude Sonnet 4.6 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Claude Sonnet 4.5 and Claude Sonnet 4.6?
Claude Sonnet 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, GCP Vertex AI, and AWS Bedrock. Claude Sonnet 4.6 is available on OpenRouter, Anthropic, AWS Bedrock, GCP Vertex AI, and Microsoft Foundry. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-05-16. Data sourced from public model cards and provider documentation.